Definitions The following terms, which are used throughout the specification, will be used and understood to have the meaning stated unless another or different meaning is specified or clear from the context.
Donor. While the term "donor" is not usually applied to the individual from whom such samples are acquired, that term, "donor" will be used here in a more general sense to include the individual from who any blood, tissue, cells or fluid is obtained for any purpose, and such term will be used to refer even to an unwilling donor. PA1 Blood. The term "blood" means whole blood and blood fractions, components, and products of blood, unless "whole blood" or a specific blood fraction, component or product of blood is stated. PA1 Povidone (USP) is used in the sense that it is used in the U.S. Pharmacopeia to describe grades of polyvinyl pyrrolidone (PVP) suitable for introduction into the human body.
GTPD triterpenoid compounds derived glycyrrhiza glabra or analogous to such compounds, the most important of which are carbenoxolone and glycyrrhizin.
Blood products such as platelet concentrates carry with them the risk of infecting the recipient with any of an number of diseases. CMV and EBV being very commonly found in such concentrates and HIV and hepititis virus being the most feared. Another organism which is frequently present in blood and blood products or fractions and which presents a serious risk in certain procedures is the bacteria Yersinia enterocolitica which is become a serious contaminant, surpassing Salmonella and Campylobacter as a cause of acute bacterial gastroenteritis. A significant increase in transfusion related infections of Y. enterocolitica has been reported, Tipple, et al., Transfusion 30, 3, p.207 (1990). Y. enterocolitica and other bacteria which propagate at relatively low temperatures, e.g. Staphylococcus epidermidis and Legionella pneumophila, present, potentially, a serious threat in blood products.
Bacterial infections, generally, are a continuing concern to blood bankers and those who produce transfusion products from blood. Indeed, a national surveillance system for transfusion-associated bacterial infections has been called for, Editorial, Transfusion 30, 3, p. 193 (1990).
In addition to the risk of transmitting infectious disease via blood or blood products, the growth of bacteria in blood and blood products at various stages of production and processing introduces pyrogens into the blood component or product which must be removed before the product can be used in therapy. Introduction of molecular iodine, e.g. povidone-I.sub.2, at an early stage in processing of blood products greatly reduces or elinfinates the pyrogen-load of the ultimate product or fraction.
Protozoa give rise to many diseases, some of great medical and economic importance. Examples of such protozoa are the genus Plasmodium, e.g. P. falciparum, P. malariae, P. ovale and P. vivax, which causes malaria, Trypanosoma, which causes Chagas' disease, and Leishmania, which cause a variety of leishmaniasis. The method of this invention is effective in eliminating these causative organisms in blood and blood products.
Generally, this invention is applicable to the treatment of donated blood and products produced from blood, tissues and fluids for inactivating virus, bacteria, chlamydia, rickettsia, mycoplasma and other potentially pathogenic microorganisms.
Among the important potential pathogens to which this invention is applicable is cytomegalovirus (CMV), probably the most ubiquitous of the pathogenic microorganisms found in animal fluids and tissues. CMV is frequently associated with, and may be a causative or contributing factor in, life threatening disease in individuals with suppressed immune systems, and can be a principal causative factor in pneumonia, neurological disorders, febrile illness, ocular disease and hepatitis. CMV infection is a serious limiting factor in the transplantation of organs, tissues and cells and the transfusion of blood and plasma from one individual to another. The kidney transplant patient runs a high risk of contracting serious, and not infrequently fatal, CMV infection from CMV introduced by the transplant organ. Recipients of whole blood, plasma, bone marrow, cornea, cardiac, and semen run a serious risk of CMV infectious disease, the risk being multiplied where the immune system of the recipient is suppressed to prevent rejection of the foreign organ or cells, or where immunosuppression is present from natural causes.
This invention has application in preventing the transmission of herpesviruses generally. Herpesviruses, of which CMV is a member, represent a very large group of viruses which are responsible for, or involved in, cold sores, shingles, a venereal disease, mononucleosis, eye infections, birth defects and probably several cancers. Three subfamilies are of particular importance. The alpha subfamily includes HV 1 (herpes virus simplex 1) which causes cold sores, fever blisters, eye and brain infections, HV 2 (herpes virus simplex 2) which cause genital ulceration, and HV 3 (HV varicella zoster) which causes chicken pox, shingles and brain infections. The beta subfamily includes HV 5, the principal member of which is CMV discussed above. The gamma subfamily includes HV 4 (Epstein-Barr) which cause infectious mononucleosis and is involved in Burkitt's lymphoma and nasopharyngeal carcinoma.
The present invention is also useful in preventing the transmission of human immunodeficiency virus (HIV). While testing has made blood products safer than it was a decade ago, the complete elimination of HIV contaminated blood and blood products has not been possible using present knowledge and technology.
It is apparent from the foregoing discussion that a method of killing or inactivating pathogenic viruses in organs, tissues, cell and fluids intended for transfusion or transplantation would be an enormous advance in medicine. It is to this major national and worldwide health care challenge that the present invention is directed.
My U.S. Pat. No. 4,891,221 describes and claims a method for inactivating virus in blood samples using glycyrrhizic triterpenoid compounds. While the use of glycyrrhizic triterpenoid compounds in blood product treatment is a major step forward, there remains a need for a method of treatment which would kill or inactivate all or nearly all pathogenic organisms, including those in the cells of the blood or blood products.
Other diseases which can be transmitted from the donor(s) to the patient(s) include the numerous diseases in which the causative pathogen appears in viable form, at least during one stage of development, in the blood, fluids or tissues of the donor. The risk can be reduced by screening potential donors and refusing to accept blood, tissue or fluids for transfer to patients; however, the availability of blood, blood fractions and products, tissues and fluids could be very greatly increased and the cost thereof greatly decreased if all potential donors could be accepted followed by killing all potential pathogens in the donated blood, fluid or tissue.
The use of elemental iodine as an antiseptic dates back to 1839. It is used today for various medicinal purposes. The combination of iodine with various solubilizing polymers led to a class of new compositions known as iodophors, which dominate the market once satisfied by simple alcoholic or aqueous iodine solutions. The iodine complexes with either nonionic surfactants, e.g., polyethylene glycol mono(nonylphenyl) ether, or poly(vinylpyrrolidone) (PVP). The complexes function by rapidly liberating free iodine in water solutions. They exhibit good activity against bacteria, molds, yeasts, protozoa, and many viruses; indeed, of all antiseptic preparations, only povidone-iodine is capable of killing all classes of pathogens encountered in nosocomial infections: gram-positive and gram-negative bacteria, mycobacteria, fungi, yeasts, viruses and protozoa. Most bacteria are killed with 15 to 30 seconds of contact. These iodophors are generally nontoxic, nonirritating, non-sensitizing, and noncorrosive to most metals (except silver and iron alloys). Medicinal povidone-iodine preparations include aerosol sprays, gauze pads, lubricating gels, creams, solutions, douche preparations, suppositories, gargles, perineal wash solutions, shampoos, and skin cleansers and scrubs. Povidone-iodine preparation are applied topically to the skin and to membranes, e.g. vaginal membranes, and in infected wounds and surgical incisions.
The uses continue to be largely medicinal, though some iodophors are used in industrial sanitation and disinfection in hospitals, building maintenance, and food-processing operations. There has been some interest in the use of iodine for purification of potable water and swimming pools. Two other iodine-containing compounds, p-tolyl diiodomethyl sulfone and p-chlorophenyldiiodomethyl sulfone have been recommended as preservatives.
Iodine and iodine-containing compounds and preparations are employed extensively in medicine, e.g., as antiseptics, as drugs administered in different combinations in the prophylaxis and treatment of certain diseases, and as therapeutic agents in various thyroid dyscrasias and other abnormalities. Iodine is a highly reactive substance combining with proteins partly by chemical reaction and partly by adsorption. Therefore its antimicrobial action is subject to substantial impairment in the presence of organic matter such as serum, blood, urine, milk, etc. However, where there is no such interference, non-selective microbicidal action is intense and rapid. A saturated aqueous solution of iodine exhibits anti-bacterial properties. However, owing to the low solubility of iodine in water (33 mg/100 Ml at 25.degree. C.), reaction with bacteria or with extraneous organic matter rapidly depletes the solution of its active content. Iodide ion is often added to increase solubility of iodine in water. This increase takes place by the formation of triiodide, I.sub.2 +I.sup.- =I3.sup.-. An aqueous solution of iodine and iodide at a Ph of less than 8 contains mainly free diatomic iodine I.sub.2 and the triiodide I3.sup.-. The ratio of I.sub.2 and I.sub.3 depends upon the concentration of iodide.
An important solubilizing agent and carrier for iodine is polyvinyl pyrrolidone (PVP), one grade of which is identified as povidone USP. Povidone-iodine (PVP-iodine), is widely used externally on humans as an antiseptic. Such products are marketed as Betadine.TM. and Isodine.TM. by The Purdue-Frederick Co.). Povidone-iodine products and the preparation of such products are described in U.S. Pat. Nos. 2,707,701, 2,826,532, and 2,900,305 to Hosmer and Siggia, assigned to GAF Corporation and in a number of GAF Corporation publications; see, e.g. Tableting with Providone3/4 povidone USP (1981) and PVP Polyvinylpyrrolidone (1982). Povidone-iodine powder contains approximately 85% PVP, 10% I.sub.2 and 5% Iodide. A 10% solution of this powder contains 1% free, available iodine. (Gershenfeld, Am. J. Surgery 94, 938 (1957)).
Under ordinary conditions, PVP is stable as a solid and in solution. The single most attractive property of PVP is its binding capability. This property has permitted utilization in numerous commercial applications. Small quantities of PVP stabilize aqueous emulsions (qv) and suspensions, apparently by its absorption as a thin layer on the surface of individual colloidal particles. The single most widely studied and best characterized PVP complex is that of PVP-iodine. For example, hydrogen triiodide forms a complex with PVP that is so stable that there is no appreciable vapor pressure. It is superior to tincture of iodine as a germicide.
Although iodine is less likely to be consumed by proteinaceous substrates than bromine and chlorine, its efficacy as a disinfectant is still reduced at certain antiseptic applications. This is due to a reducing effect of the material to be disinfected which leads to the conversion of iodine into non-bactericidal iodide. Thus, not only the reservoir of available iodine is diminished but also the equilibrium of triiodide is influenced as well. Both of these effects cause a decrease in the proportion of free molecular iodine, the actual anti-microbial agent. When povidone-iodine preparations are contaminated with liquid substrata (e.g. blood, etc.) there is, in addition. the dilution effect characteristic of povidone-iodine systems which causes an increase in the equilibrium concentration of free molecular iodine. To what extent the latter effect compensates for the other two effects depends on the content of reducing substances. Thus with full blood, a strong decrease of the concentration of free molecular iodine occurs, while, in the presence of plasma, it remains practically unchanged. Durmaz, et al, Mikrobiyol. Bul. 22 (3), 1988 (abstract); Gottardi W, Hyg. Med. 12 (4). 1987. 150-154. Nutrient broth and plasma had little inactivating activity but 1 g hemoglobin inactivated 50 mg of free I; experiments with .sup.125 I showed that uptake of I by [human] red cells occurred rapidly. Optimal antimicrobial effects in clinical use should be achieved in relatively blood-free situations. Povidone iodine produced a potent and sometimes persistent bactericidal effect towards bacteria on healthy skin. Lacey, R. W. J Appl Bacteriol 46 (3). 1979. 443-450. The bactericidal activity of dilute povidone-iodine solutions is inversely proportional to the concentration of the povidone-iodine solutions and is inhibited to the greatest extent by blood, followed by pus, fat and glove powder. Zamora J L; Surgery (St Louis) 98 (1). 1985. 25-29: Zamora, Am. J. Surgery, 151, p. 400 (1986); see also, Waheed Sheikh, Current Therapeutic Research 40, No. 6, 1096 (1986). Van Den Broek, et al, Antimicrobial Agents and Chemotherapy, 1982, 593-597, suggests that povidone-iodine is bound to cell wall proteins leaving little for interaction with microorganisms in the liquid phase (See, also, Abdullah, et al., Arzneim.-Forsch./Drug Res. 31 (I), Nr. 5, 828). Ninneman et al, J. of Immunol. 81, 1265 (1981) reported that povidone-iodine was absorbed in serum albumin and it is know that povidone-iodine is bound to albumin but it has been discovered that the antibiotic activity of povidone-iodine is not destroyed by albumin bounding. Whether the activity remains because the albumin povidone-iodine is active or whether povidone-iodine and/or I.sub.2 are released from the albumin-povidone-iodine complex.
The teachings of the prior art suggest that neither elemental (diatomic) iodine nor complexed iodine, e.g. PVP--I.sub.2, would be an effective and reliable biocide in a fluid or in a body, e.g. blood, packed or concentrated cells, organs, etc. in which massive amounts of protein are be available to react with the iodine.